Josh Melver, a Vista Ridge resident and running coach, took this photo of the burning playground at Erie's Black Rock Elementary around 4:45 a.m. June 18. (Courtesy Josh Melver)

Erie police arrested four suspects, three of them juveniles, on suspicion of arson Thursday in connection with a playground fire at Black Rock Elementary School late last month.

Many neighbors in the nearby Vista Ridge neighborhood saw the 50-foot flames coming from the preschool playground of Black Rock Elementary, 2000 Mountain View Blvd. in Erie, early in the morning of June 18.

Mountain View Fire Rescue and the Lafayette Fire Department quickly put out the fire. An investigation determined the cause was likely arson.

The St. Vrain Valley School District estimated the damage at between $50,000 and $80,000. The school district has ordered new equipment and expects to have restored the playground by the time school starts in the fall.

Santino Maryland, 18, and three juveniles, two of them 17 and one of them 16, were arrested Thursday on charges of second-degree arson, Erie police said in a news release. All four suspects are from Erie.